机械强度可靠性灵敏度分析的拟蒙特卡罗法

虽然蒙特卡罗方法具有程序结构简单,计算效率与问题维数无关的优点,但工程结构的失效概率往往很小,要获得精确的结果就需要大量样本,因而计算效率低.针对这一问题,采用Halton序列代替伪随机数并结合重要抽样方法,提出计算可靠性灵敏度的拟蒙特卡罗法.该方法与传统蒙特卡罗法相比显著减少了样本,提高了计算效率,并且误差是确定的.以齿轮为研究对象,通过对接触疲劳可靠性及可靠性灵敏度进行分析,证实了该方法在计算效率上的优势.

Reliability-based Sensitivity Analysis of Mechanical Strength via Quasi-Monte Carlo Method

Although the program structure of the Monte Carlo method is simple and bears no relation to the computational efficiency and dimensionality of the problems to be studied, lots of samples are needed to get precise results because the structural failure probability is often very small, and the computational efficiency is therefore reduced. For this reason, the quasi-Monte Carlo (QMC) method is proposed introducing the Halton sequence instead of the pseudorandom numbers to compute the reliability-based sensitivity, combining it with the importance method. The QMC method can reduce obviously the number of samples, in comparison with conventional MC method, with the computational efficiency improved and the errors definitely given. The superiority of the QMC method in computational efficiency has been verified via the analyses of the contact fatigue reliability of a gear and its reliability-based sensitivity.